X5 Vs Thea...

[Chiefer]

Hi everyone --

I hadn't seen this thread before -- it's been interesting to read through it.

Chad, your kitchen is looking good. But the flowers outside your house are all floating about 12 inches above ground!

I've been playing with X5 Phoebe a bit, and Jintu's settings he shared earlier in this thread were very helpful. The X5 raytracer is definitely much faster than X4, and the "passes" approach is also much less frustrating than the old "squares" method.

I thought you might be interested in seeing a test I ran of Phoebe vs. Thea. This is a scene from a project I'm working on (a library/office adjoining a home theater room). There are a few minor differences in the scenes, with the two most notable being the sun angle and the leather on the desk chair. But other than that, they are the same.

Image 1) the biased Thea version (Final Gathering) -- 3 minutes 7 seconds.
Image 2) the unbiased Thea version, 191 passes, 11 hours.
Image 3) the Phoebe X5 raytraced version -- 191 passes, 4 hours 10 min.

[I had to set up the Thea version to run overnight, so I let the Phoebe version run for the same number of passes for a good comparison. Interesting that it took less than half the time.]

So, what do you think? What differences do you see? The thing that jumps out at me is Phoebe's seeming inability to consistently render good metal textures. The polished aluminum on the desk chair looks good, but look at the office fan housing, which is brushed nickel. In the Phoebe rendering, it looks black. Why the inconsistency?

I'm not sure whether Phoebe is a biased or unbiased renderer, but since it's now running passes, that tends to make me think it's unbiased. So it should be able to do decent metals. But even the quickie biased Thea version has decent brushed nickel. Maybe I have something set wrong in Phoebe?

The good news: I'm very pleased with the quality of the Phoebe image, especially in light of the time it took. I really, really want to like Phoebe enough to give up Thea because it's so much more convenient.

But the bad news is: Despite the hassle of having to export from Chief to Thea, I still can't envision switching over at this point, at least not for my final versions where the client expects super high quality.

In Thea, I have so much more control over both lighting and materials, and both of those are crucial to getting a realistic (not just nice-looking) raytrace. Thea's Material Lab can be intimidating at first, but once you learn what all those controls do, it becomes second nature and then you can't imagine giving up the ability to fine-tune anything and everything.

Sorry for the long post, but I got curious about the differences and wanted to run my own test, and thought some of you would be interested.

Hi Dr. K, Very educating view of the two Raytracers. You should repost this in your blog. Good learning material.

Phoebe seemed unbiased because it also seemed to be path tracing but it is not. Photon Mapping is a biased ray tracer.

Phoebe still needs a lot of improvement but I'm quite happy with the way I want my renders appear with the current raytracer. Getting what you want with any raytracers needs time. Below is a resized example why I like Phoebe. I saved this in BMP for higher quality and resave as jpeg for compression.